1. Field of the Invention
The present invention generally relates to a development device used in an image forming apparatus such as a copier, a printer, a facsimile machine, or a multifunction machine capable of at least two of these functions, a process cartridge incorporating the development device, and an image forming apparatus incorporating the development device.
2. Description of the Background Art
In general, electrophotographic image forming apparatuses, such as copiers, printers, facsimile machines, or multifunction devices including at least two of those functions, etc., include a latent image carrier on which an electrostatic latent image is formed and a development device to develop the latent image with developer. The developer is either one-component developer consisting essentially of only toner or two-component developer consisting essentially of toner and carrier.
Differently from methods in which toner is attracted to a development roller or magnetic carrier particles, there are image forming apparatuses that employ a so-called hopping development method in which toner (i.e., toner particles) used in image development is caused to hop along a surface of a developer carrier.
For example, JP-2007-133387 discloses a development device using a toner-carrying member that is disposed facing a latent image carrier and includes multiple electrodes arranged at a predetermined pitch in the circumferential direction of the toner-carrying member. The multiple electrodes cause the toner to hop along the surface of the toner-carrying member. An identical A-phase repetitive pulse is applied to every other electrode among the multiple electrodes, positioned at even-numbered arrangement positions, and an identical B-phase phase repetitive pulse, separate from the A-phase repetitive pulse, is applied to the other electrodes, positioned at odd-numbered arrangement positions. With this configuration, an alternating electrical field is generated between any two adjacent electrodes that in turn generate an electrostatic force that causes the toner to hop between adjacent electrodes. The toner hopping along the surface of the toner-carrying member is attracted to an electrostatic latent image formed on the latent image carrier, thus developing it into a toner image.